1. Technical Field
The present invention relates in general to an improved pointing stick device for a notebook computer, and in particular to an ergonomically enhanced notebook computer force-controlled pointing stick device.
2. Description of the Prior Art
The interactive computer system operating environment, such as that encountered by users of personal computers and the like, is characterized by efforts toward increasing ease of operation and improved ergonomics. An important contribution to making the operation of such computers easier and more convenient is the graphical user interface (GUI). A GUI provides a computer interface that is visually oriented and includes a variety of graphical artifacts displayed on a computer display that make the operation of the computer more intuitive, thereby increasing user efficiency.
A GUI operating system enables a user to move a computer display pointer by using a GUI pointing device, such as a display mouse or track ball, that is attached to the computer. Generating a control input by moving the mouse across a desktop or rolling the track ball in its cradle moves the pointer across the display in the same direction of movement, according to a response function of the pointing device. The relationship between pointing device control input and pointer response on the display screen is intuitive to the user.
Many GUI systems permit multiple programs to be represented simultaneously on the computer display as different display windows. The boundaries of the windows can be adjusted or can be reduced to an icon representation. To activate a program, or to re-enter it, a user targets the display pointer within the desired program window or targets the display icon representing the program and presses a button of the display mouse or track ball device. Pressing the button, also referred to as “clicking” it, activates or re-enters the program. To activate a program without the GUI, a user would need to type the name of an executable file and provide it to the operating system. In this way, the keystrokes needed to activate or re-enter a program are eliminated or at least substantially reduced, making the computer easier and more convenient to use. The ability to point to a desired activity makes learning the operation of the computer easier and more convenient.
Additional improvements to program interaction through graphical user interface display pointer control are rapidly being achieved. For example, IBM Corporation has introduced a display pointer control feature called TrackPoint™ that includes a small, substantially rigid joystick-type actuator imbedded in the center of an otherwise conventional “QWERTY” computer keyboard. The TrackPoint control actuator is located between the G, H and B keys, which are between the hands of a typist at the home position, and is sufficiently short so that it does not interfere with normal typing on the keyboard. A computer user can apply lateral forces to the control actuator with his or her index finger to move the pointer around on the computer display, rather than using a display mouse.
The keyboard provided with the TrackPoint feature includes a pair of click buttons that are located below the middle of the space bar. These buttons duplicate the functions of the display mouse buttons and are easily depressed with a thumb. In this way, the user's hands do not need to leave the keyboard to control the display pointer. The index finger and thumb of the same hand can simultaneously control the joystick-type actuator and either of the click buttons. A keyboard with such an integrated pointing device is especially desirable in a portable computer, having a graphical user interface, where it can be inconvenient or difficult to connect and/or use a mouse or track ball with the computer to control display pointer movement. The IBM Corporation notebook computer is commonly referred to as a ThinkPad™ computer and includes a TrackPoint control actuator of the foregoing type.
The TrackPoint control actuator and associated click buttons significantly reduce the time required for a user to select windows, icons, text commands and other displayed features of a GUI over the conventional approach of manipulating a mouse or track ball physically separated from the keyboard. In addition, the TrackPoint control actuator and associated click buttons are particularly well suited for portable computers which are often used in airplanes, automobiles and other locations that do not have sufficient space for operation of a separate mouse or track ball.
The IBM TrackPoint control actuator which heretofore has been incorporated into commercially available computers typically has a resilient convex cap with a rough “cat's tongue” surface, and a diameter of about 7 mm. Although this design provides the user with good control, it protrudes up above the top or touch surfaces of the keyboard keys. In addition, the firm cap can be uncomfortable for some users as it deforms the user's finger, and its rough surface abrades the skin with can callus the fingertip. When these elements are combined with the convex shape of the current design, which does not provide the user with significant surface area for finger contact, the need to rely more friction/texture is increased. Moreover, novice users may consider the design to be unintuitive because the shape implies that it is a joystick, and thus expect the actuator to move more freely in the x-and-y-axes. Thus, an improved control actuator that overcomes these limitations would be desirable.